Question about 2004 Jeep Grand Cherokee

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P0505 I replaced the engine idle control and did not read the instructions so I did not adjust it for length. After it was still causing the P0505 again I took it out read the instructions and adjusted it for length. I am still getting the P0505 and it is idling worse than ever. 1. Could I have damaged it? 2. How can I tell if the plunger was at full extension when I adjusted it? I pulled the plunger off my original old valve when trying to kpull it to full extension so I am leery of pulling on the new one.

Posted by Donald Reed on

  • Donald Reed Nov 29, 2012

    I tried Shaun's solution and it did not change the light. The TB was really cruddy so I'm glad I did it. Shoud I try to remove the negative cable a few more times and cycle the key as suggested?



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This is one of those things where you really have to take it to a dealership. Because they way you adjust the idle control valve pendulum is with the DiamlerChysler Scan tool that all dealership service departments have. It's called the DRB scanner. After you remove and replace the IAC valve the scan tool performs a procedure call resetting the engine values. This will set the pointed pendulum on the IAC motor to sit to the throttle body. What I would tell you to do is remove the entire throttle body and clean it very good. All you will need is can or two of carburetor cleaner I use Berryman B-12 chem cleaner seems to work best for me and a old tooth brush. Remove the TPS and IAC motor from TB and clean any and all the carbon build up. So when you reinstall the IAC motor the pendulum will sit properly. If there is carbor build up in the TB no matter what you do it will not idle properly. The only parts and supplies you will need is a can or two of carb cleaner, old tooth brush, and a new TB to intake manifold gasket or O-ring. You may spend around $20.00 for everything. And this next is important. While you are working on the TB. Remove the negative battery cable from the battery post. And when you reinstall the TB. Reconnect the battery cable post. This will sometime reset all the engine sensor valves itself. After that put the key in the ignition and turn it on but don't crank it. Do that 2 or 3 times for around 5 to 10 seconds each. This may save you a lot of money instead of going to a dealership and paying those absolute ridiculous hourly rates. I worked for Jeep, Chysler, Dodge for several years in the R and D department. There usually always a back door. You just have to know where it is. Ha!! Hope this helps.

Posted on Nov 28, 2012


raj somaiya

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For details regarding following error codes,check the link below:----

Diagnostic error code P0121,P0505,P1000,P2101,P2104, P2110,P2135,P2106 ?


Posted on Nov 28, 2012


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SOURCE: code p0505 fast idle

look for a vacume hose or intake leak squeeze vacume line to brake booster and if idle changes if so bad booster

Posted on Aug 13, 2012

Richard Scordino

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SOURCE: Error code P0505 and rough idle with surge

The code you have is difinitely idle air control motor. I guess you could check continuity and compare to a known good unit, but this test may not be valid. Before condemming it though, make sure "business end" is clean and free of carbon or varnish. That applies to passage into plenum as well. If everything is clean then replace unit.

Posted on Jan 08, 2009

Andy Lebel

  • 94 Answers

SOURCE: 2004 Jeep Grand Cherokee. Keeps stalling, engine

P0505 means the whole Idle Control system, not only the IAM. Check all related sensors (i.e. crankshaft sensor). Check with a voltmeter direct at the connector of the IAM if you get any signal. Remove the IAM from the TB, connect him, let someone switch your ignition key to ON. The IAM need to drive in/out for a short time to find the right position. Hold the IAM near a hard part, that they cant drive out completely! If IAM works fine, check the fuel pressure, check and clean your TB ( if not done yet). If that doesn't work, come back again please

Posted on Oct 27, 2009

Jonah Oneal

  • 14092 Answers

SOURCE: Will a faulty MAP Sensor on a 1998 Jeep Grand


Posted on Oct 06, 2010


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SOURCE: Knocking noise. Overheated engine, warped heads,


Posted on Oct 20, 2010

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